Production of pure by-products from resin-containing liquors



PRODUCTION .oF runs nir-Paonticrs f mom ausm-comma motions Edward n. menen, columbus, omo' YAppueeuon Maren 1r., razz, seein No. stessi isolano. lorenz-'w j `'nie invention relates to the production of hishly. purified rosin, and resinous by-products :from low-grade sources, and more particularly it I concerns a process for the separate recovery of,

crystallizable rosin and rosinsalts of high purity, *and valso relatively pure mixture of fatty acids and oily substances, from certain raw materials v such as'the waste liquors produced in thesub phate and` soda processes of -wood pulp manu# Jilfactura .The present invention is inpart a continuation v of co-pending application serial #310,111, filed October 3rd, 1928l for Method of purifying resins. During the pulping of woodbyalkaline pulping l5 processes, the cellulose of the wood is separated` Jfrom the other substances such as .ligneous matter, resins andyvarious organic decompositionl products, water and chemicals which togetherl are designated black liquor. Accompanying the resins in thefblack liquor. there are varying l amounts of 'various oxygen-containing organic compounds such as fatty acids or oily substances.

and possibly others of an alcoholic nature such as pine oil, which are derived from the wood in the these compounds present in the wood varies con'- siderably, depending upon such factors as the species and age of the-tree, thepart of the tree fromwhich the wood is obtained, the soil, etc.

In `the alkaline pulpine processesthe resins and oily substances are believed to occur in the form of water soluble salts or soaps. These maythen be' decomposed by treatment with a mineral acid, w or by means of a suitable acid gas as disclosed in my Patents #1,693,586 and #1,810,472; The' rosin and said oxygen-containingcompo'unds thus reo leased are then dissolved in a suitable solvent therefor-,such as gasoline, kerosene, naphtha, or gasoil.,- -v "lf According toethe invention described in mycopending application#172,821, ld Marcha, 1927, and in prior applications, a solution of rosinV in a volatile solvent -is distilled under high vacuumA at temperatures .below 275? Qs-preferably by a.

4"' flash-'vaporizing procesawhereby rosin is distilled' overheadoin the presence of a substantial portion of the solvent, and the rosin .is recovered practically undecomposed.A :After its condensation inwell-known manner,either in the presence of the solvent or separately therefrom,- the purified rosin is treated in manner to produce a neutral water soluble' resinate which is of ai grade highly satisfactory for use in the soap industry and others. However, when the' crude rosin, from which the solution to bethus treated chemical digestion thereof. vThe amounts ofv 'odor'.

VWeight of was formed, been secured from certain sources` and contained an imusually high percentage of the oily substances or fatty acids, the final products were extremely dlmcult to obtain in pure form.. L

I have now. discovered that the solvents used j possess the property under certain conditions ofextracting from mixtures containing .rosin and other oxygen-containing compounds and decomposition productor-such as crude black liquorfw and concentrates associated therewithnot only the'rosin content thereof but also various coloring ande odor-producing bodies, which renders the mixture cloudy and which subsequently must be removed prior to distillation of the mixture .inA

`order to renderthe rosin produced fully satis;-

factoryfor many purposea'as for instance, the manufacture of neutral sodium resinate andv high grade rosin. lMoreover, I have determined ermeri-v mentally'that inthe distillation of such a solu- 20 tion of resine-lf thev concentration of the rosin in solution is too higlL-thcn upon the distillation overheadv of such concentrated solution 1mder` high vacuum temperatures below. 275 C., in the v manner indicated in my Patentv #1,810,472;.the 25 nnal distilled,y product or rosin-fatty 'acid mixture frequently will have .an objectionable burned wood Furthermore, when such distilled 'rosin istreatedinthemannerdescribedinmycopend- `ing application Serial No. 172,821, for the manufacture therefrom of sodium resinate, there is at times a notable tendency for certain objectionable impurities to, precipitatefout with the resinate upon removal of the water.- ,l

I have now discovered that these objectionable 5 coloring andv odor-producing bodies caribe eliminatedbydiluting thesolntionof rosinprior to the distillation with sumcient ofthe solvent vto reduce the rosin concentration to a point where.

the aforementioned impurities will precipitate 40 out when the solution is. cool. While the proportion of these impurities which precipitate.

upon'cooling dependsesomewhat upon the degree l of dilution with the solvent, Ihave found that eu of suon impurities are removed when a concentration of ,approximately 1I part -by` Y rosin' or fucili-fatty` acid mixture t0'. 6

or'mor'e parts of solvent is employed.

The brownish-black mass of impurities'thus -preoipiteted upon dilutingv the eooi soiuuod or rosin sinks to the'bottom of the containing vessel upon sett1ing,`or to the water line if water vis present, and the-clear solution of rosin, solvent,.and fatty. substances may be decanted, illtered,l or otherwise separated from the impurities.

While the composition of the removed impurities is not known, they are believed to be in the nature of glucosides.

According to the present invention, while the concentration of the rosin or total rosin-fatty substance mixture present in 'the solution being distilled is preferably adjusted in the ratio of 1 part by weight of the former to 5 or 6 parts of contain in certain instances pine oil and other oily substances of an alcoholic nature,-tend When present to distill with the rosin and,-when in substantial amounts in the rosin solution,- render the solution generally unsuitable for rese inate manufacture; In some instances their presence prevents the precipitation of granular resinates or crystals. Particularly is this true where the fatty or oily substances are present in amounts equal to or greater than the rosin. Moreover, when 'such a mixture of rosin, fatty acids and oily substances are distilled under vac-A uum by the methods in use prior to my invention, sufficient decomposition of either the rosin or fatty acids or both occurs to form products, the presence of which'in the mixture in the amount formed prevent crystallization of the rosin, when it is desired to produce it instead of the resinate. Neither the rosin nor the fatty substances thus obtained can have a high commercial value because of the presence of the other.

Applicant has discovered that these fatty or oily substances and other suchoxygen-containing compounds may be effectively separated from the rosin and recovered, so as concurrently to render the rosin crystallization practicable while -recovering a valuable product having many commercial uses.v This is preferably accomplished in connection with the step of distilling under high vacuum the solution of rosin and the said substances, under conditions inhibiting their decomposition and that of the rosin,-the latter remaining behind as a still product. A high grade of mixed oily substances or fatty acids is thus produced, employing a high vacuum distillation, preferably using av form of flesh-vaporization hereinafter more specifically described,- at high temperatures but below the normal 'distillation point of the rosin. `The distillation of the fatty or oily substances may if desired be carried out under high vacuum alone andwithoutl flash-vaporizing the mixture. When kerosene is employed as the Solvent, the fatty acid fraction distills over between 180 and 250 C.,

` under a vacuum of 28-29 inches of mercury.

The fatty or oily substances are then condensed either in the presence of the solvent or separate therefrom, and are recovered. The rosin remaining in the still is suitable for use in making crystallizable rosin,-o r it may be used for making resinates such as described in my copending application Serial No. 172,821 ywithout further distillation for purifying purposes.

According to another modification of the in-I vention, the solution of rosin and the said oxy-v gen-containing substances is distilled under high vacuum, preferably by means of a flash-Vaporizing process described above, at temperatures be- 1ow'275" C.,and preferably around 25o-260 C., when using a` vacuum of 28-29 inches of mercury. The distillation is so performed that the mixture of rosin, oxygen-containing substances including fatty acids, and the organic solvent distill overhead. The rosin and fatty acids are condensed in the presence cfa partat least 'of the organic solvent;l The condensate is then concentrated and cooled as necessary, whereupon the rosin crystallizes out, leaving the fatty acids and other oxygen-containing substances behind in the solvent. Under the distillation conditions-named, substantially no rosin decomposition occurs. In the event that there is a sumcient amount of the fatty acidsand other oxygen-containing substances, liquid at normal temperatures, present to servel both as a rosin VAsolvent and. to so reduce the distillation temperature under the conditions named as to prevent decompositio'n during distillationthe amount of solvent to be added to dissolve the rosin can be correspondingly reduced. In fact, if a sufficient amount of such oxygen-containing substance is present or added, no additional rosin solvent need be used.

When it is desired to convert the fatty acidfree rosin to sodium resinate, after the removal of the distillable fatty substances and the like therefrom, the rosin is dissolved in a solvent such as kerosene or gasoline, preferably in amount such as to give a solution containing around one part by weight of rosin to two or more partsof the solvent. The rosin in this solution is then reacted at suitable temperatures., preferably around the boiling point of water, with a dilute aqueous caustic soda solution or its equivalent,-the caustic alkali being present in amount sufficient to neutralize about '70% of the rosin. A clear solution containing these substances is thereby produced, which is well adapted to insure intimate contact of the reactive agents. The said solution,-which under some conditions may exist as an emulsion,is then heated to vaporize the water and a portion of the solvent,-the latter of which in major part at least is replaced continuously or intermittently to avoid the development of too lgreat a concentration of rosin in the solvent. As soon as the water is distilled substantially completely away, precipitation of thesodiumresinate occurs in the form of crystals or granules in lamount depending upon such factors as the concentration of reactants and the degree to which the oily and fatty substances and impurities previously have 'been eliminated from the rosin.

Under the conditions named above, approximately 50% of the neutral resinate precipitates upon cooling to around room temperature,-the balance remaining in the mother liquor which still contains some rosin in solution, from which the precipitated resinate is filtered. 4The latter is then washed with a suitable liquid such as clean erate birefringence, sign of elongation in-` dex of high ray equals 1.57`plus, crystal probably orthorhombic. The crystals are small, five times as long as their width. The width of -the crystals ordinarily is about ve microns 4(.005 mm.).

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.The material consists ora matted aggregate of these tiny crystals apparently free from otherA of the present invention. Referring more particu-- crystalline substances.

Prior to the lpresent invention, when sodium resinate was precipitated in the manner hereinbefore described, `it has been impossible to precipitateA or crystallize'all of the residual resinate in the mother liquor by the simple addition to the hot liquor of additional caustic alkali in aqueous solution, even by alternately heatingand cooling, because o'f the fact that the boiling point of the water-'present in the alkaline solution is .so much lower than that of the rosin- 'resinate-solvent of the mother liquor that an imsolution of rosin in a rosin-solvent'such'as kerosene a dilute aqueous solution of caustic alkali This colloidal solution or emulsion, either heated or unheated; is flowed, preferably in fine streams, into the hot mother liquor, or into'a hot solution of rosin in'a rosin solvent, maintained at a temperature wellabove the normal boiling point of temperatures around 190 to 200 C. As the emul-y sion strikes the highly heated kerosene, the water present is very quickly evaporated at the surface ofthe liquid, and is removed by suitable apparatus, thus insuring the absence from the body of hot vsolution of suilicient water to cause the formation ofa jelly or grease such as is normally formed by mixturesof water, alkali, rosin, and solvent when there is present an insumcient amount of free rosin to prevent it. As a result of the constant additionY of the above-described solution to the-"body of mother liquor or rosin solution, there is a continuous precipitation from the latter of the desired neutral resinate. After the vessel containing the treated mother liquor contains suilicient sodium resinate and the mixture is of a thick consistency, the latter is withdrawnland is filtered while hot in a filter press or centrifuge, and is then washed with clean solvent and dried.

It will therefore be recognized by -those skilled in the art that by distilling the fatty compounds and otheroxygen-containing compounds from the rosin, and the removal therefrom of certain coloring and odor-producing materials, applicant has succeeded both in rendering dark, low grade rosin and residues sufficiently freefrom these substances to permit the production of crystallizable rosin. and high grade resinates from certain raw materialsnot otherwise adapted for iarly in the-soap industry.

The accompanying drawing illustrates diagrammatically apparatus adapted for the practice centrated soap or resinous mass skimmed from such black liquor",or other rosin-bearing material containing oily or fatty substances and rosin in the presence of an alkaline solution,- is fed into the mixing tank 3, through the inlet valve of hopper l2'. To this material in tank 3 is added a suitable volume of a rosin solvent such as kerosene,naphtha, gasoline, or. the like,'fro m either the solvent tank 5 or the tank 6. Within the mixing tank 3 the mixture of rosin-containing substance and solvent is treated with an acid, preferably by the continuous passage therethrough of an acid or acid substance in Vgaseous form, such as SO2-or the waste gases from a black ash furnace-althoughsulphuric or other mineral acid, or an acid salt such asnitre cake, may be employed. `l In the form of the invention shown, sulphur dioxide is produced in a sulphur burner 2, the latter of which is supplied with air by -th`e pump I.

The rosin and certain organic acids and oily substances when present, are'dissolved in the solvent as rapidly as liberated by the acid or acid gas. 'I'he tank 3 is provided with agitating means 3l. As-the treatment with hot acid gas proceeds, the mass is heated to a point promoting the release of the rosin and oily .and fatty substances. In the' event that a mineral acid vor a cold acid gas is -'used, the mixing tank 3 is provided with a heat-- ing coil for maintaining a suitable temperature facilitating the rosin releasing reaction.

The tank 3= is provided with a reflux condenser l, which is so operated that any solvent volatilized or Amechanically carried out of the mass by the acid gases being withdrawn, is condensed and re` turned to the still; .Y Y 1 As already indicated, the solvent employed is preferably a hydrocarbon such as gasoline or kerosene, and is added in such amounts as to provide a ratio of total rosin andoily or fatty sub'- stances to solvent of from one part by weight of the former to 5 or more parts of the solvent.

The acid-treated mixture is then forced by pump l2 either directly to tl e settling tanks l or indirectly thereto throughs filter (not shown).`

The mixtureis then permitted to settle in the tanks l, whereupon it separates into three layers; i. e. (a)V aloweraqueous layer containing the water soluble salts resulting from the black liquor treatment, and which may be returned by the pump I3 to the recovery room of the pulp mill;

(b) a middle'layer containing some water and solvent and certain bodies insoluble in the cold dilute rosin solution as well as in the lower aqueous layer. This middlel layer may be ltered to recover any solvent and rosin therein. The filtrate is` allowed to stand and a water layer which forms is separated and 'returned ,to the recovery room ofthe pulp mill to recover sodium salts therefrom. AV solvent layer-which likewiseA forms is added to the layer vie) herebelow de- The insoluble' material (nigger) upon A the filter is fed to the` black ash furnace of the mill. A top layer (c) which contains a solution of rosin, fatty substances and other oxygen-containing compounds; in a rosin solvent.Y This top layer yields a clear solution when the acid-treated mixture'has beensuitably diluted and the precipitate therefrom settled, as hereinbefore de--' scribed. This dilution may be effected vby fiowi ing additional solvent into the material in tank The solution forming the top layer is then forced by pump I to the storage tank II, from which it is fed as needed to a regulator tank 8.

From the latter the pump I4 forces it under pressure into a preheater, shown diagrammatic'ally at 9, wherein it is heated while under pressure to a temperature between 175 and 250 C., depending upon such factors as the amount of solvent present, the boiling point of the solvent, and the degree of vacuum under which the subsequent distillation is to be eected.

The preheated rosin solution is then sprayed or otherwise finely dispersed into the vacuum still I5,` which is provided with a bubble-plate column or dephlegmator I l5, in which the pressure upon the solution is suddenly released, while maintaining the said temperature. The temperature and degree of vacuum are maintained such that, under the influence of the partial pressure eifect of the solvent, the oily or -fatty substances are vaporized and flow overhead from' the upper part of the column to the primary condenser I6, while the rosin is unvaporized and remains behind as a still product.

Any condensate formed in condenser I6 is reiluxed and returned to th'e still I5. The uncondensed v apors ow to condenser I1, the latter of which is maintained at a temperature adapted to condense the oily and fatty materialspresent in the vapors. The condensate is recovered in the receivers I8.

The more volatile solvent vapors then flow to condenser 25, and are there condensed and passed to receivers I9, from whence pump 2l returns them to the solvent tank 6.

A vacuum preferably of 27 or more inches of' `mercury is maintained upon the still,-induced by suitable means not shown.

When it is desired to produce a high grade crystallizable rosin from the dark res'inous still residue in still I5, it is flowed in molten form or in solution from the receivers 21 by means of the pump 20 into the tank 24 where a rosin solution is prepared containing 1 or more parts. by weight of solvent to each part of rosin. The rosin solution may then be flash-distilled in a still such as the still I5, at a temperature between 240 and 275 C. and under high vacuum of around 4 mm. of mercury, as described in my Patent #1,693, 586,-the rosin and solvent being distilled. overhead and the former condenser in the presence of a. portion at leastof the solvent, from which it is subsequently crystallized upon suitable con-- centration and cooling of the distillate.

If the said dark still residue is -to be used for the manufacture of my neutral water soluble resinate, the former is forced in uid or molten form from receivers 21 vby pump 2l into mixing tank 24 having agitating means 3l. In the tank 24 the impure rosin is dissolved in rosin solvent which may be drawn from tank i by pump 26. 'I'he resultant rosin solution, preferably containing 1 part by weight of rosin to at least 2 parts of solvent, is then forced by pump 23 to tank 34 where it is treated and agitated with an aqueous solution of caustic alkali, as previously described. The resultant colloidal solution or emulsion, either in cold or heated condition, is then introduced by pump 40 into the body of hot liquid vin the still 3l through spray nozzles. The said body of solvent is fed to the still by pump 26; and the still is heated, as by steam coils 4|. The still may be provided with agitating means. In the form shown the materials inthe still are agitated by rapid circulation of the same within the still by means of recirculating pump 32 and interconnecting valve-controlled lines. 'I'he water and any solvent distilled away during this treatment are condensed in 33, and the condensed solvent is separated from the water in separator 36,'thesolvent being conducted to storage tank 6, under action of the pump 35.

Precipitated sodium resinate is withdrawn periodically or continuously from the still 3| under the inuence of pump 32, and is fed to the centrifuge 29, where it is whizzed and Washed with fresh rosin solvent fed thereto by pump 26. The solvent thus extracted flows to solvent tank 30, from which it is returned to the solvent tank -5 for reuse through float-controlled pump 45.

' Ihe thus-purified resinate is withdrawn from the resinate in well-known manner, and if desired may be further washed or treated to remove traces of `the said rosin solvent or solvent odors.

It will be understood by those skilled in the art that when the raw materials from which the highly purified rosin is to be recovered contains rosin in its free form as such, in the absence of alkali resinates, and with or without the presence therewith of fatty or oily compounds and other oxygen-containing substances, the step of mixing and pretreating such raw materials with an acid or acid gas hereinbefore mentioned may be omitted, and the rosin is dissolved directly in a rosin solvent and is treated from that l point in accordance with the steps herein set forth. It is likewise to be understood that the rosin solution produced in 'the mixing vessel 24 may be used for the production of a highly puriiied rosin instead of for the manufacture' of sodiun resinate. 'I'he mixture of fatty substances and other oxygen-containing organic compounds' While certain organic solvents have been spe l cically mentioned in the case, it is to be understood that the invention is in nowise limited to the use of such solvents. On the contrary, any rosin solvent is suitable for use,` providing that it is liquid at normal atmospheric temperatures,-that it is substantially insoluble in Watan-and that it has a vapor-pressure higher than that of rosin. Such solvents as the various water-insoluble higher aliphatic, alcohols, chloroform, carbon disulphide, ethers, monochlorbenzol and other chlorinated hydrocarbons and esters such as'ethyl acetate. and-oleic acid, or mixtures thereof may be employed.

'I'he invention is susceptible of modification within the scope of the appended claims. 1. The process of recovering rosin from alkaline liquors containing resinates, which comprises the step of passing an acid gas through the said liquor in the presence of a volatile water-insoluble rosin solvent, thereby concurrently liberating and dissolving at least part of the rosin content of the said liquor.

2. The process as defined in claim 1 in which the said acid gas comprises a sulphur dioxidecontaining gas.

3. In the process of recovering rosin from alkaline pulping .liquors containing resinates, the step of passing therethrough a sulphur dioxide-containing acid gas in amount suficient to neutralize at least a part of the resinates contained therein to form rosin, while concurrently maintaining in the reaction mixture a volatile waterinsoluble rosin solvent in amount suflicient to dissolve the rosin thus formed.

4. The process as-dened -in claim 3 together with the steps of adjusting the concentration of rosin in the solvent to 1 part by weight of the former to 5or more parts of the solvent, separating the rosin solution from any precipitate thus formed, and distilling the rosin solution under high vacuum at a temperature below that at which substantial decomposition of the rosin occurs.

5. The process as dened in claim 3, including the further steps of adjusting the concentrations of rosin and solvent to 1 part of the rosin in 5 or more parts of the solvent, separating the rosin solution from any precipitate thus formed, `preheating the solution under pressure to a temperature at which under atmospheric pressure fatty acids present in the solution are Vaporizable but the rosin is not vaporizable, flash-vaporizing the preheated solution under a vacuumized receptacle, distilling overhead the fatty acid components, and condensing and collecting the same, and separately recovering the residual rosin.

6. The process of recovering rosin from alkaline liquors containing resinates, which comprises passing therethrough a sulphur dioxide-containing acid gas in amount sufficient to neutralize at least a part of the resinates contained therein to form rosin, while concurrently maintaining the resultant reaction mixture in a water-insoluble rosin solvent in amount by weight 5 or more times that of the rosin dissolved therein, separating the rosin solution from any precipitated matter thus formed, and recovering the rosin from the said solution.

7. The process of purifying crude mixtures containing rosin and fatty acids, which comprises the step of distilling alsolution of the said mixture in a volatile water-insoluble solvent under high vacuum at temperatures adapted to remove the fatty acids overhead substantially undecomposed while retaining the rosin in the form of a still product, separately condensing and recovering the fatty acids and solvent distilled overhead, and recovering the purified rosin.

8. The process'as defined in claim 7 in which the said distillation is carried out at temperatures not higher than 260 C.

9. The process of purifying crude mixtures containing rosin and fatty acids, which comprises the steps of preheating a solution of the said mixture in a. water-insolublev rosin solvent to from 175 to 250 C. under pressure, thereafter nashvaporizing the resultant solution intoa. vacuumized receptacle maintained at a temperature adapted to affectA distillation overhead of the fatty acids and solvent substantially undecomposed while below that at which the rosin is distilled over, separately condensing and recovering the fatty acids and the solvent, and recovering the rosin.

10. In the process of recovering rosin from alkaline pulping liquor containing resinates and fatty acid salts, the steps which include passing through the said liquor a sulphur dioxide-con- A taining acid gas in amounts sufficient to neutralize a substantial portion of the resinates contained therein to formi rosin and fatty acids,

While concurrently maintaining in the reactionv mixture a volatile water insoluble rosinsolvent rosin and fatty acid solution under high vacuum at a temperature adapted to remove overhead the fatty acids in substantially undecomposed form `while retaining the rosin in the form of a still product, separately condensing and recovering 4the fatty acids and the solvent, and recovering the purified rosin.

11. 'I'he process of purifying distilled rosin containing fatty acids and derived from wood pulping liquor, which 'comprises crystallizing the distilled rosin from a solution thereof in-.a liquid having a higher vapor pressure than that of rosin, the said solution also having dissolved therein the said fatty acids, andseparating the rosin from the solution Aof fatty acids.

12. The process of purifying crude mixtures containing rosin dissolved in fatty acids, which comprises distilling overhead under 'high vacuum the rosin and fatty acid content of a mixture containing rosin and sufficient fatty acids to dissolve the rosin and 4to substantially lower the distillation temperature thereof, condensing the rosin vapors in the presence of a portion at least of the said fatty acids, and crystallizing the rosin in the presence of the last-named portion of fatty acids.

13. The process of recovering rosin from alkaline liquors containing resinates and higher fatty acid salts, which comprises passing therethrough an acid gas in amount sufficient to neutralize at least a part of theresinates contained therein to form rosin and fatty acids while the said liquors have admixed therewith a water-insoluble rosin to provide a mixture having one part of total rosin and fatty acids for each five or more parts of solvent, forming the said mixture into a plurality of layers including a layer of 'a solvent solution of rosin and fatty acids, separating the latter layer from the mixture and preheating the solution, spraying the preheated solution into a vacuumized receptacle thereby vaporizing the same, condensing the vaporized rosin and fatty acids in the presence of a quantity of the said solvent `substantially less than the amount of total rosin and fatty acids condensed, and sep'- arating the rosin from the fatty acids and solvent.

14. The process of recovering rosin from alkaline liquor containing resinates and higher fatty acid salts, which comprises mixing the said liquor with a water-insoluble rosin solvent having a, higher vapor pressure than that of rosin, passing an acid gas through the resultant mixture in amount sufficient to neutralize at least a part of the resinates contained therein to form rosin and fatty'acids, adjusting the amount of the said solvent in thevmixture to provide therein a ratio of one part of total rosin and fatty acids to at least 5 parts of the solvent, separating the mixture into a plurality of layers including one madevup of a solvent solution of rosin and fatty acids, and separately recovering from the lasta layer consisting of a solution ofl rosin and fatty acids in the volatile rosin solvent, and a layer containing water, solvent, and some rosin, fatty acids, and bodies insoluble in both thesolvent and in water, filtering the lastfnamed layer, separating the water from the resultant filtrate, and separately recovering therefrom the rosin and the fatty acids.

16. The process of recovering rosin from alkaline liquors containing resinates and fatty acid salts, which comprises converting the resinates and fatty acid salts into rosin and fatty acids, distilling the rosin' andfatty acids from the resultant mixture at temperatures not substantially above 275 C. and in the presence of a waterinsoluble rosin solvent having a higher vapor pressure than rosin, and crystallizing the distilled rosin from a solution thereof in the said rosin solvent, thereby separating the rosin from the fatty acids and solvent, and separating the fatty acids from the solvent.

17. The process of recovering rosin from alkaline liquors containing' resinates and fatty acid salts, which 'comprises converting the resinates and fatty acid salts into rosin and fatty acids,

distilling at least the fatty acids from the resultant mixture under vacuum in the presence of a hydrocarbon having a higher vapor pressure than rosin, and at a temperature substantially below that at which decomposition of the rosin and fatty acids occurs, condensing and recovering the fatty acids, and recovering the rosin.

18. 'I'he process of recovering rosin from alkaline liquors containing resinates and fatty acid salts, which comprises converting the resinates and fatty acid salts into rosin and fatty acids, A

EDWARD H. FRENCH. g5 

